Biometrics authentication generally employs a matching method using feature points. The matching method using feature points performs matching based on feature values calculated from an image in the vicinity of characteristic points (feature points) extracted from the image. As illustrated in FIG. 15A, a branch point 1501, end points 1502 and 1503, and so on in a biological image 1500 of fingerprints, veins, or the like are extracted as feature points, and the feature values are calculated from an image around the feature points (see FIG. 15B).
In the matching process, for example, after both of registration data and matching data are approximately positioned and normalized, the feature values contained in the registration data and the feature values contained in the matching data are compared to search for the feature points of a paired matching image with respect to the feature points of the registered image. For example, for each of the feature points of the matching image whose spatial distances from the feature points of the registered image are equal to or less than a threshold, a feature value score indicating the degree of similarity of the feature value of each feature point between the registered image and the matching image is calculated, and a feature point of the matching image having the most similar feature value is selected and paired based on the calculated feature value score. The obtained feature value pairs are sorted based on the search results of all obtained feature points using the feature value scores, as illustrated in FIG. 16. The average of the higher-order feature value scores is obtained, and the score is used as the final score in the authentication in the matching process.
An object detecting apparatus has been proposed which binarizes an identifier corresponding to the detected object and a feature value generated from observation data based on predetermined threshold information (the number of thresholds and the values of the thresholds) to thereby speed up a process for calculating the inner product of the identifier and the feature value for use in an identifying process.
Examples of the related art include Japanese Laid-open Patent Publication No. 2016-9379.